I forgot to mention that my last UOA (only had 1125 miles on the oil) showed 2.15% fuel. Shortly after that UOA, I had compression and leak-down tests done on my bike (~18,000 miles at the time of the tests), and they showed engine compression to be as nearly perfectly even as one can get, and sealing extremely well. Carbs had also been cleaned before the UOA, and I normally commute fairly long distances on the freeway (~35 miles one-way). So, fuel in the oil is quite 'normal' for these bikes.

That's an interesting article. I'll have to read it more thoroughly at some point. Off-hand, it sounds like a lot of it is not particularly pertinent to our bikes, but mostly I was confused as to how the author cited AHRMA work showing higher power output but more frequent overhaul when crankcase air pressure is reduced, but later asserted that better crankcase breathing would allow _less_ frequent overhauls. I missed any actual data or evidence in between that would allow him to jump from the one to the other. Still, it bears reading more thoroughly.

 

Personally, I would agree with reducing your warm-up times. As far as riding in a lower gear at higher rpm... I probably wouldn't. Your style will put more load on the engine than riding at a higher rpm but the same speed would. So, your style will actually reduce fuel in the oil just a bit vs. running higher rpm (but lower % of total load/available output). Ironic, isn't it?

 

yeah i noticed the article was pointing mainly towards really, really early model bikes. maybe even before engineers developed crank case breathers?? still interesting though.

the longer i own this cbr the better i get to know its pros and cons. especially good to know there isnt a real problem with the bike, going off what i have heard from mechanics and people on here. on the gas in oil issue, im being a little paranoid or over cautious. lol, now i know what some people mean when they say "shut up and just ride it, the bike will let you know when it has a major problem".

sounds like to me i have a "normal" amount of fuel in crankcase. for now im good on the fuel in crankcase issue, i have found my answer here and by talking to mechanics. i will keep an eye on the oil level and smell it every time before i ride. the only thing i can suggest to anyone who has the same concern is to do the same. or just have an analysis done on oil, compression test on cylinders, and check for sticking floats in carbs.

if i have any problems or updates concerning fuel in the crankcase on my f4 i will post it here.

thanks

 

I had the same probl..i had like a gal of fuel in the crankcase. i changed out my spark plugs and it dident start after that so i must have flooded it took it to the shop cause i had no clue wtf was the probl.. he took the carbs off and changed the jet, floats ,and sinked them all back in changed the fluids ..im still havin probl..wit keeping the bike running seems to be wit the carbs ,ive been playin wit the idler **** seems to help a bit but will see ...Let me know what you find out it may help me too.. hope it all works out for you